1. Field of the Invention
The present invention relates to an object distance computing method and an object distance computing apparatus, and particularly relates to an object distance computing method and an object distance computing apparatus which can increase a computable range for the object distance information.
2. Description of the Prior Art
In recent years, a smart electronic apparatus becomes more and more popular. Besides the smart phone and the tablet computer, the smart TV is a popular smart electronic apparatus as well. Comparing with a traditional TV, a user can use a gesture to control a smart TV rather than use a remote controller. For a smart phone and a tablet computer, the gesture is directly performed on a surface thereof. However, for a smart TV, the gesture is always performed at a location which is not very close the smart TV. In such case, in order to accurately detect a complicated gesture, 3D image detection becomes very important. For example, in FIG. 1A, the user U performs a “grabbing” gesture. For another example, in FIG. 1B, the user U opens his hand and moving the hand back. It is hard to determine such gesture if the 3D image detection is not performed.
Different from a normal plane image, the 3D image detection needs a distance parameter. Accordingly, the 3D image detection has a mechanism for detecting an object distance. Conventionally, the mechanism for detecting an object distance is applying a light source to emit light, and computing the object distance based on the light reflected from the object. For such apparatus, the cost is high and the size is large, since the light source and the apparatus for controlling the light source and for receiving reflected light must be included.